Widely considered to be the first virtual reality head-mounted display (HMD) this amazing-looking contraption was created by Ivan Sutherland back in 1968 when he was working as a researcher at the University of Utah.

For those not familiar with the story of Roman myth: Damocles was one of Nero’s courtiers, who would often tell the Roman Emperor how it must feel amazing to have such wealth and power. Nero eventually offered him the chance to trade places with him for a short while to experience what it was actually like. When Damocles sat on the throne, however, he notices a sword hanging over his head, suspended by a single strand of horsetail hair. Nero’s not-so-subtle point that great power usually comes with great risk is actually quite a nice metaphor for immersive technologies which have such great potential but are also scarily effective in altering human perception and behavior.

The device itself was nicknamed as The Sword of Damocles primarily for the huge mechanical arm attachment that followed users around the room, permanently suspended above their heads. The environments projected were rudimentary wireframe rooms, but it did change perspective based on the position of the user’s gaze, and was an early proof of concept for head tracking, which of course paved the way for much of the amazing VR technology we’re seeing today.